Quoted By:
being that this site is infested with neets still living with Mommy and never having been on a building site or even done some basic home diy work I'm going to do you the favor of breaking down the inspirations for Grubbin's whole evolution line.
There are no stun guns, no tram carts and no railguns involved. I know all you've got in life to reference by is vidya games and public transport so I understand why the connection aren't obvious.
Far left is what's called a multimeter. You clamp it around wiring to check if there's a current running through it. Typically these are brightly coloured - specifically yellow and orange just like Grubbin. Expect the anime to reveal how grubbin can sense electricity or some such shit.
In the middle there is a battery charger. Guess what it does? It charges batteries. Oh hey just like how Chargabug charges up Vikavolt, or is earthed by being buried etc. This is not exactly rocket science.
On the right is a wire strippers. Look at the little notches on the blades. Now look at Vikavolt. Now back again I'm fucking your sister. Now later when the anime has an episode about how Vikavolts drained the town's power supply you can remember this old-man anon who was right about everything.
